See "contrib/slapd-modules/comp_match/README" to understand
what's the purpose of  this patch is and how to use it.

clarify that the names of the configure statements are case-insensitive, despite style considerations lead to use uppercase for some and lowercase for others

with code to accept old values.

using the same op structure, such as in refint overlay, cause a memleak
otherwise.) Probably should be using tmpmem for this.